Physical Quantities

• Units

  Time - Seconds (s)

  Temperature - Kelvin (K) / Degree Celsius

  Length - Metre (m)

  Mass - Kilogram (kg)

  Volume - Cubic Metre (m^3)
• Time


  • measured in seconds(s)
  • Using stopwatch
  • degree of accuracy using digital stopwatch is 2.d.p
• Temperature


  • measured in Kelvin (k) or degree celsius
  • Kelvin + 273 = celsius
  • Degree of accuracy for thermometer is 1.d.p (0.0 or 0.5)
• Length


  • measured in metres (m)
  • 1m = 10dm = 100cm = 1000mm (all X10)
  • dm is decimetre
  • Using metre rule or measuring tape
  • degree of accuracy for metre rule is 1.d.p
• Mass


  • Measured in kilogram (kg)
  • 1 kilotonne(kt) = 1000 tonne(t) = 1 000 000kg = 1 000 000 000g = 1 000 000 000 000mg [x 1000]
  • Using electronic balance
• Volumeof liquids


  • measured in m^3
  • refer to length for conversion to dm^3 and cm^3
  • Pipette - 1.d.p (Fixed volume - 10.0cm^3 or 25.0 cm^3)
  • Volumetric flask (fixed volume)
  • Measuring cylinder - 2.d.p nearest 0.5
  • Burette - 2.d.p nearest 0.05
  • when reading, position eyes at meniscus to avoid parallex error
• Volume of gases


  • using gas syringe
  • measured in m^3